Earlier in the day, the northern Aleppo province was hit with a new escalation in the violence as a helicopter, believed to belong to Syrian government forces, dropped barrel bombs in a deadly attack on Turkey-backed opposition forces in the border area, Turkish officials have claimed.

Getty Images

A member of the Syrian Civil Defence, known as the White Helmets, evacuates a child following reported government shelling on the rebel-held town of Douma

Getty Images

A wounded Syrian man receiving treatment in a makeshift hospital in Douma, which was also hit by raids

The field commander of Syria’s pro-government troops has said any Turkish advances in northern Syria under the pretext of fighting IS militants would be dealt with "forcefully and appropriately."

The barrel bombing was said to have hit the village of Tal Madiq, in a part of northern Aleppo where rival groups have been operating, mostly to rout Islamic State militants.

If confirmed, the attack would be the first by Syrian government forces on the Turkish-backed fighters.

Turkey's state-run news agency didn't say when the attack happened but said at least two Syrian opposition fighters were killed and five others wounded.

AP:Associated Press

The Syrian Civil Defense group known as the White Helmets, run through the damaged buildings after airstrikes in the village of Hass

But a Syrian opposition spokesman claimed the attack took place Tuesday.

The Syrian Observatory's chief, Rami Abdurrahman, said helicopters struck while intense clashes were underway between Kurdish-led fighters and Turkey-backed forces in Tal Madiq.

He said that 11 Syrian opposition fighters and five Kurdish fighters were killed in the assault.

The Kurdish-led forces are now in control of the village, about 10 miles away from the highly prized IS-controlled town of al-Bab.

USS-ARMADA

STEPPING UP THE FIGHT

JIHAD’S YOUR LOT

Warped ISIS fanatics celebrate after ‘drawing straws’ to win the chance to launch the next suicide bombing

carry on bombing

Putin to continue bombing of 'the innocents' in Syria saying deaths are a 'sad reality of war'

A senior Kurdish commander, however, denied Syrian government bombings of the Turkey-backed fighters, saying it was an attempted explanation for battlefield losses.

Mahmoud Barkhadan of the People’s Protection Units in the Syria Kurdish militia, told the Associated Press: "They are trying to find a pretext for the loss. No aircraft were involved.”

A spokesman for the Syrian fighting group, Nour el-Din al-Zinki Yasser al-Youssef, said the Kurdish-led forces attacked them while they were fighting IS militants in the area.

It was then that Syrian government helicopters followed.

Getty Images

Smoke billows following an air strike by Syrian government forces in a rebel-held area of Daraa

AP:Associated Press

Terrified children being pulled away from the school attack in Hass.

Getty Images

A distraught and wounded child being treated in a makeshift hospital in Douma

The complex terrain is a powder keg and confrontation among rival groups can break out anytime.

Ankara, the capital of Turkey, sent tanks, troops and aircraft into northern Syria in August in an unprecedented incursion it claimed was part of efforts to help the Syrian opposition clear the border area of Islamic State fighters.

But Ankara is also seeking to contain the U.S.-backed Syrian Kurdish forces fighting the IS group, putting it at odds with its key ally, the United States.

Syria's military last week threatened to shoot down any Turkish warplane that enters Syrian air space, after Turkish jets raided villages in northern Syria in an escalation of Ankara's offensive against Kurdish fighters.

AP:Associated Press

A look from a distance of the airstrike in Hass

Getty Images

A child wanders past a damaged building in the town of Douma

On Wednesday, a statement from the field commander of pro-government troops said Turkish advance under the pretext of fighting IS in northern and eastern Aleppo is an encroachment on the Syrian government's area of operations and would not be tolerated.

The fall of the IS controlled town, al-Bab, to Turkey-backed rebels would threaten the Syrian government's siege on the rebels in the city of Aleppo, to the west.

Getty Images

Many wounded children have been taken to Douma's makeshift hospital

Meanwhile, Turkish Foreign Minister Mevlut Cavusoglu told reporters on Wednesday that Turkey is determined to push ahead with the offensive in northern Syria dubbed Operation Eurphrates Shield and liberate the town of al-Bab from IS militants.

“Such attacks will not stop us from combatting Daesh,” he said.

“The Euphrates Shield operation will continue. The only goal of the Euphrates Shield operation is to clear Daesh from this area.”